HEI, Inc. provides engineering, product design, automation and test, manufacturing, distribution, and fulfillment services and solutions. It operates two segments, Microelectronics and Advanced Medical Operation. The Microelectronics segment offers high density miniaturization solutions, including services from front end development through the full production process; specialized substrates, which are used as platforms for microelectronic assembly; engineering services for creative technological solutions; improvement and lean flow manufacturing; the ability to develop and implement a range of test software and hardware solutions. The Advanced Medical Operation segment provides design, development, validation, and verification services for medical box build products and software interfaces for Class I, II, and III medical devices; transitional manufacturing services for medical products; and contract manufacturing and service work for medical box build products. HEI, Inc. serves various markets, including hearing, medical device, medical equipment, communications, computing, and industrial equipment in the United States, Canada, Mexico, Europe, and the Asia Pacific.